JPS62147149A - Neutral position detector - Google Patents

Abstract

PURPOSE:To dispence with a mechanical switch by comparing a change gear ratio of a memory means corresponding to a shift stage of a change gear with another change gear ratio of an engine speed sensor to can speed sensor so as to judge a neutral position. CONSTITUTION:An electronic controller which has a constant speed running unit and receives signals of a clutch SW3, a brake SW6, a set SW4 and a resume SW5, computes a change gear ratio from the present output of an engine speed sensor consisting of a permanent magnet PM1 directly connected to a crankshaft and a lead SW1, and a can sped sensor consisting of a permanent magnet PM2 connected to a speed indicator cable and a lead SW2. And the electronic controller compares it with the change gear ratio corresponding to the shift stage of a present change gear read out from a memory means and judges it to be a neutral position at the change gear ratio is not within an allowance after elapse of a set time of a SM timer. This can remove a disadvantage of a mechanical switch.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a neutral position detection device that detects a neutral position, and in particular, to a neutral position detection device that detects the position without using a neutral position detection switch or the like. This invention relates to a neutral position detection device.

[Prior Art] As a conventional neural position detection device of this type,
One example is a means for detecting the neutral position using a microswitch or the like. The neutral position detection means uses a microswitch to detect when the shift lever is moved to the neutral position, and determines the position by operating the microswitch.

[Problems to be Solved by the Invention] However, when a mechanical switch is used to detect the neutral position, it is difficult to automatically stop the engine by automatically stopping unnecessary idling of the engine while the engine is temporarily stopped.
In the case of a starter device, it is possible that an abnormality such as contact trouble in the mechanical switch may delay the timing of automatically stopping idling or may prevent idling from being stopped.

Alternatively, in a constant speed traveling system, if the shift lever is pulled out without the clutch being depressed, there is a possibility that the engine rotation will run out of control.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a neutral position detection device that can detect the neutral position without using a mechanical switch.

Means and operation for solving problem E] The neutral position detection device according to the present invention includes a vehicle engine rotation sensor, a vehicle speed sensor, an engine rotation sensor and a medium speed hinge according to the shift stage of the transmission. a storage means for storing a gear ratio; a comparison means for comparing the gear ratio of the storage means according to the shift stage of the transmission with which gear ratio of the engine rotation sensor and the vehicle speed sensor during running; and an output of the comparison means and a timer for determining that the time difference is not within a predetermined time tolerance range. When the gear of the transmission is not in a predetermined gear position, the gear ratio between the engine rotation sensor and the vehicle speed sensor is determined to be within a tolerance, and then it is determined that the vehicle is in neutral position.

[Example] Hereinafter, as an example of the neutral position detecting device of the present invention, a constant speed traveling device including the neutral position detecting device will be described.

FIG. 1 shows an overall configuration diagram of a constant speed traveling device equipped with a neutral position detection device according to an embodiment of the present invention.

In this configuration, the lightning control filtration device CPU is constituted by a single-chip microcomputer, and includes a storage means that stores a gear ratio between an engine rotation sensor and a vehicle speed sensor according to a shift stage of a vehicle transmission, and a speed change ratio of the storage means. The vehicle is equipped with a built-in timer for determining whether the output of the comparing means continues for a predetermined period of time. Reed switch SWI that detects engine rotation signal
, a reed switch SW2 that detects a vehicle speed signal, a clutch switch SW3 that detects depression of a clutch (not shown), a brake switch SW6 that detects depression of a brake (not shown), a Z switch SW4, and a resume switch SW5. is input. Also, a negative pressure actuator A controls the opening degree of the throttle valve SV.
A vacuum pump BP generates a negative pressure to operate C, and the output of a vacuum switch SW7 disposed in a surge tank ST that stores the negative pressure is input. Furthermore, the output of the throttle sensor is input.

Here, the resume switch SW5 is used to restart the once-released constant speed driving control at the stored throttle width, and the clutch switch SW3 and the player switch SW6 are used as constant speed driving control release switch means. It is.

A permanent magnet PM1 fixed to a crankshaft (not shown) is arranged near the reed switch SW1, and when the permanent magnet PM1 rotates due to engine rotation, the contacts of the reed switch SW1 open and close, and the engine speed changes. A pulse (engine speed signal) with a frequency proportional to is sent to the electronic control 2II device CPU. That is, the permanent magnet PM1 fixed to the crankshaft A foot and the reed switch 5W1 constitute an engine rotation sensor.
A permanent magnet PM'2 connected to a speedometer cable (not shown) is arranged near the reed switch SW2, and when the permanent magnet PM2 rotates as the vehicle moves, the contact of the reed switch SW2 changes to I? fl (A
A pulse (vehicle speed signal) with a frequency proportional to the vehicle speed is sent to the electronic control unit CPU. That is, the permanent magnet PM2 and the reed switch S connected to the speedometer cable.
W2 constitutes a vehicle speed sensor.

The clutch switch SW3 opens and closes in conjunction with the vehicle's clutch pedal, and the brake switch SW6 opens and closes in conjunction with the vehicle's brake pedal. Brake switch SW
A stop lamp L is connected to 6, and the stop lamp L lights up when the brake switch SW 6 is turned on (closed).

The set switch SW4 and the resume switch SW5 are push button switches, and are arranged at positions that are easy for the driver to operate. By pressing the set switch SW4, the vehicle speed is memorized and constant speed driving control is started.
Although constant speed driving is canceled by pressing the brake switch SW6, the memorized vehicle speed remains. Resume switch SW5
If you press , constant speed driving control will be started at the memorized vehicle speed before constant speed driving was canceled.

Note that power is supplied to the brake switch SW6 via a fuse F, and power is supplied to the electronic II control unit CPU via a power switch SWO.

The output of the electronic control unit CPU is to drive the solenoid of a control valve V1 that controls a negative pressure actuator AC, which will be described later, through a fjJ circuit D1, the solenoid of a vent valve V2 through a drive circuit D2, and a release valve ■3.
These solenoids are connected to each other via a drive circuit D3. It is connected to the motor of the vacuum pump BP and the like via a drive circuit D4.

The negative pressure actuator AC is configured as follows.
Operate.

The negative pressure actuator ΔC constitutes a negative pressure chamber A1 sealed by a diaphragm A4 disposed within the housing A5, and the opposite side of the diaphragm A4 is an atmospheric side A2. The diaphragm A4 is energized by a compression coil spring Δ3 disposed on the side of the negative pressure chamber A1. Note that a throttle rod B1 that opens and closes a valve B2 of a throttle valve Sv is connected to the diaphragm A4.

Further, in the negative pressure chamber A1 of the negative pressure actuator AC,
Negative pressure from the surge tank ST is introduced through a control valve v1, a vent valve V2, and a release valve v3.

The control valve v1 sends the negative pressure of the surge tank ST to the negative pressure actuator AC side when the solenoid is in an energized state, and shuts it off when the solenoid is in a non-energized state. Also, the solenoid of vent valve v2 is energized! When this occurs, the negative pressure sent from the control valve v1 side is sent to the negative pressure actuator AC side,
When in the de-energized state, the negative pressure on the negative pressure actuator AC side is discharged to the atmosphere. When a malfunction occurs in the control system and proper control becomes impossible, the release valve V3
The negative pressure in the negative pressure chamber Δ1 of the negative pressure actuator AC is discharged to the atmosphere, and the f1 pressure chamber A1 is brought into an atmospheric pressure state.

At this time, the throttle valve Sv is pushed back by the throttle rod B1 and closes the valve B2. Normally, the solenoid of the release valve V3 is in an energized state, and the vent valve V2 and the negative pressure chamber A1 of the negative pressure actuator AC are in communication.

The control valve v1 and the vent valve V2 are controlled in duty ratio by an electronic control unit CPU. That is, during constant speed driving control, the stored vehicle speed is compared with the vehicle speed at that time in the electronic control unit CPU, and the duty of the signal that excites the solenoid of the control valve V1 and vent valve 2 is adjusted so that the difference between the two is equal. Determine the ratio. For example, when deceleration is required, the duty ratio is reduced, and the proportion of time during which atmospheric air is communicated from the vent valve V2 to the negative pressure actuator AC is increased.
The throttle valve Sv is closed by the Diane ram A4. Conversely, when acceleration is required, the duty ratio is increased and the negative pressure actuator AC closes the throttle valve Sv.
Space out v.

Next, the operation of the microcombination unit of the electronic control unit CPU will be explained using flowcharts 1 to 1 of FIGS. 2 to 13.

Ignition switch is on, i.e. power switch S
When WO is turned on and this program starts, the memory is initialized in step 1.

At this time, "Dawn state control flow 1" of the control state S=0 of the control state branch program is set. In step 2, the states of each switch SW1 to SW7 are read.

Step 3 is a branching step in which the control state S is determined and a processing surface is selected accordingly.

That is, this program branches according to each control state,
Since it is programmed to function according to the branched program, the control state S is specified for each function and the flow processing of each control state is started.

Since the control state S-0 is set in step 1, the "standby state control flow J" of S-O is entered in step 3.

Control state s=o:r is a state control flow. In this flow, the operation state of the resume switch SW5 is detected and the control system is put into a cancel state.

When entering this flow, first, in step 01, all valves are
That is, the control valve V1 and the vent valve V2,
The release valve V3 is turned off, the control of the negative pressure actuator AC is stopped, and the constant speed running control is stopped.

Then, in step 02, the operating state of the resume switch SW5 is detected. Step 0 when turned on
Check the memorized vehicle speed in step 3, and find that the memorized vehicle speed is 01m/h (clear state @
), in step 04, the control state S=1 is set to "full-on control flow 1", and in step 05, a vacuum bomb flag is set to put the vacuum pump BP into the operating state (set to "H11").

That is, preparations are made to enter "full-on control flow j" in control state S-1.

Further, when the resume switch SW5 is not turned on or when the stored vehicle speed is O1 m/h (clear state), the control state S is not changed because the resume function is denied.

Control state S=1: rFull-on control flow This flow performs prospective control in order to quickly drive the negative pressure actuator AC to a predetermined position. That is, the control state rl! : In the "deceleration control flow J" of S = 4,
Control valve ■1 is off, and the pressure in negative pressure chamber A1 of negative pressure actuator AC has decreased.
In the "standby control flow", when the main constant speed driving control is entered,
Alternatively, since the negative pressure in the negative pressure chamber A1 of the negative pressure actuator AC does not match the set speed since it is after the "cancel control flow", the constant speed traveling control can be continued as is, and the control valve This is because even if the duty ratio is controlled in (1), the predetermined throttle opening cannot be reached immediately. Therefore, in step 11, it is determined whether this flow is entered for the first time, and when it is entered for the first time, all valves V1, V2, and V3 are turned on in step 12, and in step 13, the length is set in advance in proportion to the vehicle speed. Set the full-on control time. After entering this flow in step 11 and setting the full-on control time,
Check the progress of the full-on control time set in step 14. When the full-on control time elapses, first, step 15
Then, turn off the control valve V1 and proceed to step 16.
Then, the control state fms-2 is set, and the r constant speed control flow j is entered.

Control state S=2: r constant speed control flow" This flow is a flow for performing constant speed driving at the stored vehicle speed. In step 201, reed switch SW2
The vehicle speed is obtained from the pulse, and the duty ratio for opening and closing the control valve V1 and vent valve V2 is determined from the vehicle speed.

Steps 202 to 207 are steps performed when the vehicle speed cannot be controlled to the stored vehicle speed for some reason in vehicle speed control using duty ratio control. First, when the vehicle speed deviation becomes greater than 151 m/h in step 205, release valve ■3 is turned off in step 206,
The negative pressure in the negative pressure chamber A1 of the negative pressure actuator AC is reduced to equal atmospheric pressure, and the Hill of the throttle valve SV is
Release ill.

Then, in step 207, the buzzer 4- is turned on and notified. When the vehicle speed deviation becomes smaller than 101fa/h, the release valve V3 is turned on in step 203, the buzzer is turned off in step 204, and the control valve ■1 and vent valve V2 are turned on in step 208.
The duty ratio control works effectively, making it possible to control the vehicle to run at a constant speed.

After this, while the vehicle speed deviation in step 202 is accelerated from 101 m/h to 151 m/h in step 205, and the vehicle speed deviation in step 205 is 15 m/h.
During the period from which the vehicle speed deviation is decelerated to 10-/h in step 202, there is a hysteresis of the set value at which control of the negative pressure actuator AC is restarted.

In step 209, the resume switch SW5 listens for a predetermined time (here, 0.5 seconds) J:1. When the top is turned on, the "acceleration control flow J" with control state S=3 is set in step 210. Then, in step 211, the set switch SW is turned on.
4 is turned on, the "r deceleration control flow" with control state S=4 is set in step 212. When the clutch switch SW3 is turned on in step 213, it is determined in step 214 whether the control state is S=1 or S=2. That is,
Since the clutch switch SW3 has a resume function, "r acceleration control flow" or "deceleration control flow J"
It is determined whether this flow is entered from either of the two flows, and if this flow is entered from either of the two flows, the "clutch resume control flow~" with control state BS=6 is set in step 215; otherwise, the "clutch resume control flow" is set. , in step 216, the cancellation control flow j for the control state S=5 of the cancel function is set as the clutch switch SW3 is turned on.When the brake switch SW6 is turned on in step 217, the control state flls=5 is set in step 218. 1
"cancel control flow" is set. Step 219
In step 220, the low speed limit is determined, and if the current vehicle speed is less than or equal to the predetermined control vehicle speed, the control state S=7 is set and constant speed driving control is prohibited. And step 221
``Starts the processing of the Baneem pump control subroutine j''.

Furthermore, in step 222, a gear ratio is calculated from the outputs of the current engine rotation sensor and vehicle speed sensor 1, and the gear ratio of the engine rotation sensor and vehicle speed sensor is calculated according to the current shift stage of the transmission read from the storage means. are compared by the comparison means, and it is determined whether the difference is within the tolerance. If the difference is within the tolerance, the 8M timer is cleared in step 223. If the difference is not within the tolerance, it is determined in step 224 whether the set time of the 8M timer has elapsed, and if the output of the comparison means is not within the tolerance until the set time set by the 3M timer has elapsed, the control is performed in step 225. Set the standby state control flow j of the control state S=O of the state branch block [1 gram]. Therefore, the gear ratio of the engine rotation sensor and the vehicle speed sensor according to the current gear shift □ is set to the predetermined gear ratio. If a state that does not exist continues for the time set by the 8M timer, it will lead to 141-year-old state control no matter what control state it is in.

Control state fis=3: r acceleration control flow This flow is a flow for updating the constant speed of the vehicle by accelerating the vehicle during constant speed driving control. First, step 31'
c'' Turn on all valves, that is, control valve V1, vent valve ■2, and release valve v3, increase the negative pressure in negative pressure chamber A1 of negative pressure actuator AC, open throttle valve S■, and turn on the resume switch in step 32. The acceleration is continued until SW5 is turned off. When the resume switch SW5 is turned off, the control state S is changed in step 33.
=2 (constant speed control) o -j is set, and the vehicle speed at that time is stored in the memory at step 34r.

Control state S=4: F deceleration control flow" This flow is a flow for decelerating the controlled vehicle speed during constant speed driving control and restarting constant speed driving control. Set switch SW4 is turned on during constant speed driving control. Then the control state S=
4, and enters this r deceleration control function.In step 41, the clutch switch SW with a cancel function is activated.
3 or brake switch SW6 is on, and if any one is on,
In step 42, all valves v1, V2, and ■3 are turned off, and the constant speed driving control after entering the deceleration control flow j is stopped.In step 41, either the clutch switch SW3 or the brake switch SW6 is turned on. If not, in step 43 the control valve V
1 and pen 1 to valve v2 off, release valve V3
Turn on.

In this way, when the negative pressure supply from the negative pressure actuator AC is cut off, the throttle valve SV gradually taps, and the vehicle speed gradually increases. In step 44, it is detected that the set switch SW4 is turned off, and in step 45, the vehicle speed at the time when the set switch SW4 was turned off is stored. Then, in step 46, unless either the clutch switch SW3 or the brake switch SW6, which has a canceling function, is turned on again and exits from the constant speed driving control,
In step 48, the control state S=1 is set, and the "full-on control flow J is entered. That is, the deceleration control is set to the set switch S.
Continues while W4 is turned on, and sets switch SW4
The vehicle resumes constant speed driving at the speed it was at the time it was turned off. When either clutch switch SW3 or brake switch SW6 is turned on in step 46, step 47
Control status rr! Set AS=5 and enter the "cancellation control flow". Then, if the set switch SW4 is on in step 44, a vacuum pump flag is set in step 4 (set to 11 Hu).

Control state S=5: ff cancel control flow" This flow is performed when the clutch switch SW3 or brake switch SW6 is
When turned on, constant speed driving control is canceled. When clutch switch SW3 or brake switch SW6 having a cancel function is turned on in step 51,
In step 52, the control state S-〇's standby state control flow'' is selected, and in step 53, all pulses 7V1, V2, ■
3 is turned off.

Control state S=6: r clutch resume control flow" In this flow, during the processing of "constant speed control flow" of control state S-2, clutch switch SW3 is turned on, and the constant speed driving control is temporarily released. , This is the flow for entering constant speed driving control again. First, in step 61, all valves V
1, V2, and V3 are turned off, and when it is determined in step 62 that the clutch switch SW3 is turned off,
In step 63, a "full-on control flow" with control state S=1 is entered.

Control State S=7: r Low Speed Limit Control Flow This flow is for canceling and clearing the stored speed when the vehicle speed is lower than a predetermined speed in steps 219 and 220. In step 71, the stored vehicle speed is cleared, in step 72, all valves V1, V2, and (3) are turned off, and in step 73, the "standby state control flow" in the control state $-0 is entered.

The above is an explanation of each control state flow.

The vacuum pump control subroutine j is controlled as follows.

“Vacuum pump control subroutine” step 221
The process starts with the "vacuum pump control subroutine". In step 81, it is determined whether the vacuum pump flag is set (“H”), and when the vacuum pump flag is set (“Hu”), the timer T1 is set in step 82.
In step 83, the vacuum pump BP is kept in operation until the set time elapses. When the set time of timer 1 has elapsed in step 82, the vacuum pump flag is lowered to "L" in step 84, and further,
At step 85, timer T1 is reset. Then, if the vacuum pump flag is not set in step 81 (when it is set), it is determined in step 86 whether the vacuum switch flag is set ("") ("), and if the vacuum switch flag is not set, it is determined whether the vacuum switch flag is set ("") ("). (When "L"), it is checked in step 91 whether the vacuum switch SW7 is turned on.If the vacuum switch SW7 is not turned on in step 91, the vacuum pump BP is stopped in step 90.In step 91, the vacuum switch SW7 is turned on. When it is determined that 5W70 is on, a vacuum switch flag is set in step 92 (set to H11).

-E+, the vacuum switch flag is set at step 92 < 11 H11), it is determined at step 86 that the vacuum switch flag is set ('H'), and timer T2 is set at step 87. Until the time elapses, the vacuum pump BP is turned off in step 83.
is activated. When the set time of timer T2 has elapsed in step 87, the vacuum switch flag is set to "L" in step 88.
Clear 2 and go to step 90 to vacuum pump BP.
to stop.

In the constant speed traveling device equipped with the neutral position detection device of the above embodiment, the gear ratio is calculated from the outputs of the current engine rotation sensor and the vehicle speed sensor, and the engine Comparing the gear ratios of the rotation sensor and the vehicle speed sensor using a comparison means, determining whether the difference is within a tolerance, and when the difference is within a tolerance,
8M timer) 7. If not within tolerance, 8
It is determined whether the set time of the M timer has elapsed, and if the output of the comparison means is not within the tolerance until the set time set by the 8M timer has elapsed, the "standby state" of the control state S-0 of the control state branching program is determined. Control flow J is set. Therefore, if the gear ratio between the engine rotation sensor and the vehicle speed sensor is not at the predetermined gear ratio according to the current shift stage of the transmission, the state will continue for the time set by the 8M timer. If this happens, no matter what control state it is in, it will lead to standby state control, and if the clutch is not operated while driving at a constant speed,
When the engine enters the normal position, the control system controls the engine speed to reach the same level, thereby preventing the engine from reaching its basic constant state.

In this example, the comparison means compares the gear ratio obtained from the outputs of the current engine rotation sensor and vehicle speed sensor with the gear ratio corresponding to the shift gear of the transmission, and determines that the difference is within the tolerance. If not, it is determined whether the set time of the timer has elapsed, and if the output of the comparison means is not within the tolerance until the set time set by the timer has elapsed, the control state g of the control state branch program, S-〇 "Standby state control flow J is set. However, if the present invention is implemented as a constant speed traveling device equipped with a neutral position detection device, the configuration is not limited to the above configuration, but the settings set by a timer. Control of the constant speed traveling device may be terminated when the output of the comparison means is not within a tolerance until the time elapses.Also,
The output f) of the current engine rotation sensor and the vehicle speed sensor in step 222 is calculated, and the gear ratio of the engine rotation sensor and the vehicle speed sensor corresponding to the current shift stage of the transmission read out from the storage means is calculated. The means for determining whether the difference is within the tolerance by the comparison means is configured to perform comparison judgment for the number of shift stages, and writes a value obtained by adding the tolerance to the gear ratio corresponding to the shift stage in the storage means. Alternatively, the value of the gear ratio corresponding to the shift stage may be written in the storage means, and the magnitude of the output of the comparison means may be further compared by the tolerance comparison means.

As described above, in the constant speed traveling device equipped with the neutral upper position detection device according to the embodiment of the present invention, the engine rotation sensor of the vehicle disposed on the engine side of the transmission, that is, the input shaft side, and the transmission a vehicle speed sensor disposed on the output shaft side of the transmission, a storage means storing a gear ratio between the engine rotation sensor and the vehicle speed sensor according to a shift stage of the transmission, and a shift speed of the storage means according to the shift stage of the transmission. comparison means for comparing the ratio with a gear ratio between the engine rotation sensor and the vehicle speed sensor while the vehicle is running;
The device includes a timer for determining that the output of the comparison means is not within a predetermined time tolerance range, and a transmission ratio of the storage means according to the shift gear of the transmission, the engine rotation sensor and the vehicle speed sensor during driving. When the gear ratio of the engine speed sensor and the vehicle speed sensor are not at a predetermined gear position of the transmission, the neutral position is determined based on the fact that the gear ratio of the engine rotation sensor and the vehicle speed sensor is not determined within a tolerance.

Therefore, when carrying out the present invention, the engine rotation sensor attached to the input side of the transmission that detects the engine rotation speed of the vehicle and the vehicle speed sensor attached to the output side of the transmission detect the gear ratio. Since it is calculated, any device that can detect the rotational speed of the input shaft and output shaft of the transmission may be used.

Note that if the sensors for detecting the rotational speed of the input shaft and output shaft of the transmission are further provided with a clutch interposed therebetween, it is possible to detect the wear state of the clutch plate.

Furthermore, the storage means that stores the gear ratio between the engine rotation sensor and the vehicle speed sensor according to the shift stage of the transmission is not limited to a digital storage means, but may be a potentiometer that generates an analog (cog-like output). The threshold value can be set to, etc.

Similarly, the comparison means for comparing the gear ratio of the storage means corresponding to shift 1 to gear of the transmission with the gear ratio of the engine rotation sensor and the vehicle speed sensor during driving is a digital and analog comparing means. be able to.

In the embodiment of the present invention, the storage means stores the gear ratio between the engine rotation sensor and the vehicle speed sensor according to the shift gear of the transmission, and the gear ratio of the storage means according to the shift gear of the transmission is stored. An electronic control unit CPU constitutes a comparison means for comparing the gear ratio of the engine rotation sensor and the vehicle speed sensor during driving, and a timer for determining that the output of the comparison means is not within a predetermined time tolerance range. Although the present invention is implemented using a single-chip microcomputer, other digital and analog circuit configurations may be used in place of the microcomputer on the Q2 actual flow side.

[Effects of the Invention] As described above, the neutral position detection device of the present invention has the following effects:
a storage means that stores a gear ratio between an engine rotation center and a vehicle speed sensor according to a shift gear of a transmission of the vehicle, and a gear ratio between the gear ratio of the storage means and the engine rotation sensor and the vehicle speed sensor during driving; The neutral position is directly detected from the shift lever via a mechanical switch. Because the neutral position can be detected without
Eliminates the drawbacks of mechanical switches.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a constant speed traveling device equipped with a neutral position detection device according to an embodiment of the present invention, and FIGS.
FIG. 3 is a flowchart of the constant speed running control operation of step 7 in the speed control system used in the constant speed running mode equipped with the neutral position detection device of the above embodiment. In the figure, BP...vacuum pump, Sv...throttle valve, AC...negative pressure actuator, ST...surge tank, CPU...electronic control unit. In addition, in the figures, the same reference numerals and the same symbols indicate the same or equivalent parts.

Claims (3)

[Claims] (1) An input side rotation sensor installed on the input shaft side of the transmission, an output side rotation sensor installed on the output shaft side of the transmission, and an input side rotation sensor and output side according to the shift gear of the transmission. a storage means that stores a speed ratio with the rotation sensor; and a comparison means that compares the speed ratio of the storage means according to the shift stage of the transmission with the speed ratio of the input side rotation sensor and the output side rotation sensor during driving. and a time limit means for determining that the output of the comparison means is not within a predetermined time tolerance range. (2) The neutral position detection device according to claim 1, wherein the input side rotation sensor is an engine rotation sensor that detects engine rotation speed. (3) The neutral position detection device according to claim 1, wherein the output side rotation sensor is a vehicle speed sensor.